Causes of the Greenhouse Effect

Taking an inventory of the causes of the greenhouse effect is like taking an inventory of human endeavor. Certain gases introduced into the atmosphere trap heat in the air, raising global temperatures. Unfortunately, we're the source of most of those gases.

The Many Causes Of The Greenhouse Effect

In a greenhouse, sunlight enters through glass walls and ceilings. This light is absorbed by objects in the greenhouse and reflected back as heat energy. The glass of the greenhouse traps the heat energy inside, keeping the greenhouse warm. In the Earth's atmosphere, certain gasses (called greenhouse gasses) perform the same function of the glass in a greenhouse-they trap radiated heat in the atmosphere. Read on to find out where these gases come from:

• The culprits. Water vapor, carbon dioxide and methane are the main contributors to the greenhouse effect in the atmosphere. Nitrous oxide and fluorinated gases also add to the problem, but at a much lower rate.
• On the road (again). The burning of fossil fuels to provide transportation accounts for 20% of the carbon dioxide released into the atmosphere. While advanced countries look for ways to reduce vehicle emissions, developing countries are rapidly expanding the number of cars on their roads.
• It's all about power. Industrial processes (like cement production) and power generation (especially coal-fired plants), produce as much as 50 percent of the carbon dioxide produced by humans.
• Farmer Brown. Agricultural activities are big producers of carbon dioxide, methane and nitrous oxide. Deforestation for farming removes the carbon scrubbing capabilities of millions of trees each year. Livestock produce methane as a byproduct of their eating habits. Artificial fertilizers produce nitrous oxide as they interact with the soil.
• Natural sources. Natural sources of greenhouse gas emissions include volcanic out-gassing, oceanic evaporation and animal biological processes. These sources tend to remain constant, although major volcanic events have spiked carbon dioxide levels, as shown by historical geologic records.